A conventional digital video recorder is formed mainly as an on-board structure in a stand-alone version. Therefore, expansion of the stand-alone version is not executed easily. That is, there was a problem because when the number of channels required by users changed, a new substrate for the conventional digital video recorder had to be manufactured. Conventional digital video recorder was generally produced with setting four channels as a basis. But, nowadays, as the functions of the digital video recorder are getting diversified, versions of digital video recorders are increasing bit by bit while connecting the digital video recorder to various kinds of outside devices. So, since the number of necessary channels is increasing, there has been difficulty in changing the number of channels.
Moreover, in a Personal Computer (PC) version of a digital video recorder, image information is transmitted to a main Central Processing Unit (CPU) through a peripheral component interconnect (PCI) slot and data bus speed is reduced according to the number of cards that are inserted into the PCI slot.